From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0AAEC2D0A3 for ; Thu, 29 Oct 2020 19:35:53 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 29913206DD for ; Thu, 29 Oct 2020 19:35:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Il4ialQN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 29913206DD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:46790 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kYDiB-0006ou-NL for qemu-devel@archiver.kernel.org; Thu, 29 Oct 2020 15:35:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41574) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kYDgj-0006Gj-2H for qemu-devel@nongnu.org; Thu, 29 Oct 2020 15:34:22 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:40926) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kYDgg-0004kJ-MG for qemu-devel@nongnu.org; Thu, 29 Oct 2020 15:34:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1604000057; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iKc+alC3GNHOWzVdJKy+wpkubdPFO4Hbe58+ItSQHk4=; b=Il4ialQNa+3ZMrZt1AMJ2GvvV4V4W7Tmotbx28aKGYCeb4QOXAoJOcrAQLAdLsNqp3Q6qu aIXYHx11bVQX1I7grtK2E6RWi4IyebpscM57NoiQQAYXfJAIA0CtlW2x3lZ445XBNTS7pz Gzbq5ZYvA+BY00Fr8U5fuQkwvej51AI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-288-AD3dRRcyP72ApUPa4BRRfQ-1; Thu, 29 Oct 2020 15:34:15 -0400 X-MC-Unique: AD3dRRcyP72ApUPa4BRRfQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 894E287950B; Thu, 29 Oct 2020 19:34:14 +0000 (UTC) Received: from [10.3.112.145] (ovpn-112-145.phx2.redhat.com [10.3.112.145]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1F73155772; Thu, 29 Oct 2020 19:34:08 +0000 (UTC) To: Markus Armbruster , qemu-devel@nongnu.org References: <20201029133833.3450220-1-armbru@redhat.com> <20201029133833.3450220-8-armbru@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Subject: Re: [PATCH 07/11] sockets: Fix default of UnixSocketAddress member @tight Message-ID: <388cd3a5-9f7f-79e0-b9ad-f5be86e4661d@redhat.com> Date: Thu, 29 Oct 2020 14:34:07 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.1 MIME-Version: 1.0 In-Reply-To: <20201029133833.3450220-8-armbru@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/29 01:47:28 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.261, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, berrange@redhat.com, zxq_yx_007@163.com, kraxel@redhat.com, pbonzini@redhat.com, marcandre.lureau@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 10/29/20 8:38 AM, Markus Armbruster wrote: > QMP chardev-add defaults absent member @tight to false instead of > true. HMP chardev-add and CLI -chardev correctly default to true. > > The previous commit demonstrated that socket_listen() and > socket_connect() are broken for absent @tight. That explains why QMP > is broken, but not why HMP and CLI work. We need to dig deeper. > > An optional bool member of a QAPI struct can be false, true, or > absent. In C, we have: > > has_MEMBER MEMBER > false true false > true true false > absent false false/ignore I'm not sure the TAB in this table made it very legible (it's hard to tell if has_MEMBER is the label of column 1 or 2). Row two is wrong: MEMBER (column 3) is set to true when the QMP code passed true on the wire. > > When has_MEMBER is false, MEMBER should be set to false on write, and > ignored on read. > > unix_listen_saddr() and unix_connect_saddr() use member @tight without > checking @has_tight. This is wrong. It generally works if addr was constructed by the same way as the generated QAPI parser code - but as you demonstrated, in this particular case, because our construction did not obey the rules of the QAPI parser, our lack of checking bit us. > > When @tight was set to false as it should be, absent @tight defaults > to false. Wrong, it should default to true. This is what breaks QMP. > > There is one exception: qemu_chr_parse_socket() leaves @has_tight > false when it sets @tight. Wrong, but the wrongs cancel out. This is > why HMP and CLI work. Same for @has_abstract. > > Fix unix_listen_saddr() and unix_connect_saddr() to default absent > @tight to true. > > Fix qemu_chr_parse_socket() to set @has_tight and @has_abstract. At any rate, the fix looks correct: - as producers, anywhere we hand-construct an addr (rather than using generated QAPI code), we MUST set both has_MEMBER and MEMBER, including setting MEMBER to false if has_MEMBER is false, if we want to preserve the assumptions made in the rest of the code; - as consumers, rather than relying on the QAPI parsers only setting MEMBER to true when has_MEMBER is true, we can ensure that has_MEMBER has priority by checking it ourselves > +++ b/util/qemu-sockets.c > @@ -919,7 +919,7 @@ static int unix_listen_saddr(UnixSocketAddress *saddr, > if (saddr->abstract) { > un.sun_path[0] = '\0'; > memcpy(&un.sun_path[1], path, pathlen); > - if (saddr->tight) { > + if (!saddr->has_tight || saddr->tight) { > addrlen = offsetof(struct sockaddr_un, sun_path) + 1 + pathlen; > } > } else { > @@ -979,7 +979,7 @@ static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp) > if (saddr->abstract) { > un.sun_path[0] = '\0'; > memcpy(&un.sun_path[1], saddr->path, pathlen); > - if (saddr->tight) { > + if (!saddr->has_tight || saddr->tight) { > addrlen = offsetof(struct sockaddr_un, sun_path) + 1 + pathlen; > } > } else { > Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org